[LeetCode] Best Time to Buy and Sell stock III

Say you have an array for which the i^th element is the price of a given stock on day i.
Design an algorithm to find the maximum profit. You may complete at most two transactions.
Note:
You may not engage in multiple transactions at the same time (ie, you must sell the stock before you buy again).

解题思路：
1. 扫描数组从左到右，算出leftmaxprofit
2. 扫描数组从右到左，算出rightmaxprofit
3. 同时从左到右扫描 leftmaxprofit and rightmaxprofit， 算出最大收益，leftmaxprofit + rightmaxprofit

Java code:

 public int maxProfit(int[] prices) {
       int maxProfit = 0;
        int[] leftMaxProfit = new int[prices.length];
        int[] rightMaxProfit = new int[prices.length];
        
        int minPrice = Integer.MAX_VALUE;
        
        for(int i = 0; i < prices.length; i++){   
            minPrice = minPrice < prices[i]? minPrice : prices[i];
            int profit = prices[i] - minPrice;
            leftMaxProfit[i] = maxProfit > profit ? maxProfit : profit;
        }
        
        int maxPrice = 0;
        maxProfit = 0;
        
        for(int i = prices.length; i > 0; i--){
            int profit = maxPrice - prices[i-1];
            maxProfit = maxProfit > profit ? maxProfit : profit;
            rightMaxProfit[i-1] = maxProfit;
            maxPrice = maxPrice > prices[i-1]? maxPrice : prices[i-1];
        }
        
        maxProfit = 0;
        
        for(int i = 0; i < prices.length; i++){
           int profit = leftMaxProfit[i] + rightMaxProfit[i];
           maxProfit = profit > maxProfit? profit : maxProfit;
        }
        
        return maxProfit;
    }